Machines for manufacturing bearing races by rolling

ABSTRACT

A machine for rolling the outer races of bearings in an external die with the assistance of a rolling tool roller operating in overhanging relationship in a race blank to be rolled, and the roller is mounted to the end of an eccentric spindle fitted in a sleeve mounted in turn eccentrically in another sleeve, wherein the two sleeves are rotatably driven, the spindle and tool roller being rigidly assembled and rotatably driven from a motor at such speed that the apparent speed of the tool roller approaching the blank to be rolled is substantially zero, the sleeves being driven through an epicyclic gear train connected through two of its rotating members to the sleeves, these two members coacting with a third member of the gear train which consists of a reaction member responsive to a member controlling the relative angular displacement of the sleeves.

United States Patent [191 Gerat et al.

[111 3,871,204 [451 Mar. 18, 1975 MACHINES FOR MANUFACTURING BEARING RACES BY ROLLING [73] Assignee: Societe Nouvelle de Roulements, Annecy (l-laute Savoie), France [22] Filed: July 13, 1973 [21] Appl. No.: 378,815

[30] Foreign Application Priority Data Aug. 9, 1972 France 72.28788 [52] US. Cl 72/117, 72/92, 72/123 [51] Int. Cl B21d 17/04 [58] Field of Search. 29/148.4 C, 149.5 C, 148.4 D; 72/115, 117, 120,122,123, 124, 126, 208, 370, 91-93; 408/150, 151

3,654,826 4/1972 Gersch 408/151 3,700,345 10/1972 Schubert 408/150 Primary Examiner-C. W. Lanham Assistant Examiner--E. M. Combs Attorney, Agent, or FirmStevens, Davis, Miller & Mosher [57] ABSTRACT A machine for rolling the outer races of bearings in an external die with the assistance of a rolling tool roller operating in overhanging relationship in a race blank to be rolled, and the roller is mounted to the end of an eccentric spindle fitted in a sleeve mounted in turn eccentrically in another sleeve, wherein the two sleeves are rotatably driven, the spindle and tool roller being rigidly assembled and rotatably driven from a motor at such speed that the apparent speed of the tool roller approaching the blank to be rolled is substantially zero, the sleeves being driven through an e'picyclic gear train connected through two of its rotating members to the sleeves, these two members coacting with a third member of the gear train which consists of a reaction member responsive to a member controlling the relative angular displacement of the sleeves.

15 Claims, 16 Drawing Figures rn r-ammms 3.871.204

SHEET UZUF 10 141 will! PATEHTED MAR] 8 I975 SHEET OBOF 10 PATENTED HAR I 8 I975 SHEET O7UF 10 Li I Lula-h ...w. x oq PATENTEBHAR 1 8 I975 SHEET 100F 10 MACHINES FOR MANUFACTURING BEARING RACES BY ROLLING The present invention relates to a machine for manufacturing ring-shaped workpieces such as the outer races of bearings, by applying the so-called rolling operation to annular blanks cut from tubular stock.

Although the manufacture of inner bearing races having their grooves formed on the outer peripheral surface can be carried out by using conventional rolling means such as external rolling tool roller machines wherein the tool rollersare mounted on members having a rigidity sufficient for transmitting the considerable distortion necessary for rolling bearing steels, the manufacture of outer races having their groove formed on the inner peripheral surface is atended by specific problems, since the diameter of the shaping roller must be slightly smaller than that of the bore of the race blank in which the rolling operation is to be performed.

Machines are already known wherein the rolling tool roller is wedged on either side of the race by means of bearings or bearing rollers transmitting the pressure stress thereto. This arrangement prevents any rapid and automatic feed and removal of workpieces, which are obviously necessary in such manufacturing processes, since the tool roller bearing wedging rollers confine the workpiece and necessitate a disassembling operation for each workpiece replacement.

Only machines wherein the tool roller is held from one side in overhanging relationship permit this rapid feed and removal from the side opposite the rollersupporting side. However, the lack of rigidity of the overhanging supports carrying the tool roller limited this technique to the hot rolling of blanks in which the bearing stresses are reduced considerably in comparison with the efforts to be produced during a cold rolling operation. Besides, hot rolled blanks must subsequently be finished to the requisite dimensions by conventional machining.

ln this particular application a hot-rolling machine for shaping races and like annular workpieces is already known wherein the tool roller mounted for loose rotation on its spindle mounted in turn in eccentric relationship in one of a pair of mutually eccentric sleeves is pressed against the blank to be shaped by the action of a hydraulic braking device adapted to change the relative angular displacement of the sleeves and therefore the eccentricity of the roller axis in relation to the blank axis.

Whereas the absence of adjustment in the pressure stroke of the tool roller, which is controlled passively by the braking action and the sudden engagement between the roller and the workpiece, is acceptable in a hot rolling operation due to the plasticity of the metal to be shaped, such absence and sudden engagement are ill-suited in a cold rolling operation because the considerable stress developed during this operation would obviously cause the surfaces in mutual contact to bind, and because the bearing pressures must be controlled with the maximum precision.

The present invention is directed to provide a machine capable of rolling an annular workpiece, notably outer bearing races, according to the cold rolling technique, with the desired dimensional tolerances and surface conditions that are usually obtained in turning of workpieces of this general character.

cally in a first sleeve of a pair, the other sleeve of the pair being rotatably mounted in the frame structure of the machine, both sleeves being responsive to drive means for rotating them and to other means capable of imparting an angular displacement thereto for rotatably driving the spindle and tool roller assembly and controlling the tool roller feed movement, is character- 1 ised in that the spindle and the tool roller are rigid with each other and rotatably driven from a motor atsuch speed that the apparent speed of the tool roller approaching the blank is substantially zero, and that the drive means comprise an epicyclic gear train operatively connected through two rotating members of said train to said sleeves, said rotating members co-acting with a third member of said gear train which is responsive to said angular displacement means, and consisting of a reaction member having its angular setting controlled as a function of the desired tool roller feed rate.

In this arrangement, the means for producing the angular displacement of said reaction member may be easily controlled notably with the assistance of a hydraulic actuator.

Thus, with this arrangement the rolling feed rate of the tool roller can be controlled in a strict and reproductible manner, as a function of the programme contemplated and consistent with the workpiece to be rolled. This control action is of primary importance, considering the magnitude of the pressures created in the roller-to-workpiece interface and applied to the roller and its spindle, these pressures being rather difficult to harmonize with the desired precision and production rates. The preliminary driving of the spindle and roller at the rolling speed is advantageous in that it eliminates the risk of binding the parts at the points of contact between the roller and the workpiece, due to the absence of relative frictional engagement between the two surfaces involved. This device is subsequently changed into the driving of the roller for rotation as a consequence ofits pressure contact with the blank during the rolling operation proper, under the control of the eccentric sleeves, but remains necessary at the beginning of each operation to avoid any relative and stray slip likely to produce any binding defect on the surface of the roller and also, of course, of the blank.

In order to obtain the exertion ofa substantially constant pressure on the roller and avoid pressure surges likely to impair its durability, the kinematic chain contemplated herein for producing the above-defined roller feed movement may easily be constructed in a reversible form. To this end, the rotation bearings are low-friction bearings such as rolling-contact bearings, especially those of the eccentric sleeves whereat the possibility of nonreversibility due to jamming or binding is most likely to develop, and at least one elastic coupling, for example a so-called Oldham joint permitting the absorption of possible axial misalignment during the operation with the sleeve in a pronounced eccentric relative position, may be provided on each sleeve driving line.

The fluid feed under constant hydraulic pressure produces a substantially constant pressure at the tool roller for only the nearly linear portion of the sine eccentricity law is utilized.

The output is adjusted from the onset and in any case has but a very moderate influence on the rolling time. The feed curve is subordinate to the output and to the constant pressure. Nothwithstanding this, the kinematic chain is reversible since the eccentricity control and the stress transmission are accomplished through continuously moving members, the coefficients of friction are constantly dynamic and therefore moderate. This accounts for the fact that in the known, abovementioned hot-rolling method a passive drive through a hydraulic brake is utilized although the rolling pressures are lower than in the case of cold rolling.

In fact, it is notorious that this kinematic chain comprising large-diameter eccentric members of moderate eccentricity or throw, coupled to high-inertia gear trains, is not reversible.

A typical form of embodiment of a machine constructed according to the teachings of this invention will now be described by way of example with reference to the accompanying drawings, in which FIG. I is a diagrammatic view of the kinematic chain of the device controlling the rolling tool roller feed;

FIG. 2 is a recorded diagram of the rolling tool roller feed during a cycle of operation ofa machine operating under constant stress condition FIG. 3 is a wiring diagram illustrating the electrohy draulic control system of the machine FIG. 4 is a sectional view showing the parallel gear trains connecting the epicyclic gear train to the eccentric sleeves;

FIG. 5 is an axial sectional view showing the mounting of the tool roller spindle and of the eccentric sleeves FIG. 6 is a sectional view of the hydraulic ram operating in conjunction with the reaction member of the epicyclic gear train FIG. 7 is an axial section showing the die carrier with its hydraulic control means for opening and closing the die. and for ejecting the workpiece and locking the die, together with the supply sump formed in the die carrier FIG. 8 is a crosssectional view of the supply sump together with the means for controlling the locking of said die FIG. 9 is a front view of the spindle supporting block provided with a deflector for protecting the tool roller FIG. 10 is a view showing the base plate of the machine and means for controlling the tipping of the die carrier assembly, to facilitate the inspection thereof and the replacement of tools FIGS. 11 to 14 are fragmentary axial sections illustrating the various steps of the blank rolling operation, and

FIGS. 15 and 16 are two cross-sectional view illustrating two steps of the rolling operation.

The rolling machine illustrated comprises in the whole (see notably FIG. 1) a spindle 1 receiving at its end a tool roller 2 and adapted to be driven at its other end by a motor 3 adapted to be reversed as a receiver operating without any antagonistic torque. A hydraulic motor equipped with a non-return valve in parallel will serve the purpose very satisfactorily. The spindle 1 is rotatably mounted in an eccentric position in a sleeve 4 (the eccentricity being designated by the reference numeral 5 in FIG. 5), and the sleeve itself is rotatably mounted in an eccentric position in an external sleeve 6 having an axis 0 merging with that of the spindle l in the inoperative position of the latter, the sleeve 6 being rotatably mounted in the spindle-carrier block 7. Both sleeves 4 and 6 are interconnected by trains of gears,

8 for one sleeve and 9 for the other sleeve. to two elements of an epicyclic geartrain designated in general by the reference numeral 10, these two elements actually consisting of a sun gear 11 of this train and of a toothed wheel rigid with a planet carrier spider or cage 12 provided with twin planet pinions 13, 14. One set of planet pinions 13 is in meshing engagement with the sun gear 11 and the other set is meshing with with a reaction sun gear 15. The planet carrier 12 is driven through a belt transmission 16 with the assistance of a motor 17 and the gear ratios of the two kinematic chains driving the sleeves 4 and 6 are so calculated that these sleeves 4, 6 revolve at the same speed. Moreover, it will be seen that any variation in the angular position of reaction sun gear 15 is attended by a relative angular displacement of sleeves 4 and 6 and therefore by a variation in the eccentricity or throw of the spindle l in relation to the axis 0, which corresponds to the feed movement of the tool roller 2, the operative rotation of the tool-roller carrier spindle 1 about the axis 0 corresponding in this case to the synchronous rotation of said sleeves.

The spindle motor 3 is provided for rotatably driving the spindle proper and, of course, the tool roller preliminary to the contact between this roller and the blank to be rolled, so that the apparent speed of the tool roller approaching and eventually contacting the blank is substantially zero. The hydraulic motor 3 is then by-passed or short-circuited to operate as a pump during the rolling operation. The angular position of the reaction sun gear 15 is controlled by means of a hydraulic ram designated in general by the reference numeral 18 via a rack 19 rigid with the cylinder 20 of this ram and co-acting with a pinion 21 rigid with said sun gear 15. To this end, the cylinder 20 is slidably mounted to a piston rod 22 projecting from each end of the cylinder 20 and secured at its ends to the frame structure of the machine. The ram movement is controlled by means of a variable-output hydraulic pump 23 responsive to an electro-hydaulic assembly 24 controlling the entire sequence of operations of the ma chine.

The spindle carrier block 7 (FIG. 5) carries about the tool roller a fixed element 25 of the die, the other element 26 of the openable die being an integral part of a movable device shown in detail in FIG. 7 and having its body 27 secured to the base plate 28 of the frame structure of the machine in front of the spindle carrier block 7. As shown in FIG. 10, this fastening is contemplated in this case about a pivot pin 29 and the bearing plate of body 27 which engages base plate 28 is pivotally connected on the other hand to the piston rod 30 of a hydraulic actuator having its cylinder 31 pivotally connected to said base plate. The function of this actuator consists in tipping the movable die carrier device to the position shown in dash-and-dot lines in FIG. 10 for carrying out any inspection operation or changing the tool, which are thus greatly facilitated.

The die section 26 is secured to a structure movable in relation to the body 27 and comprising a hydraulic ram piston 32 having its cylinder formed in said body 27, and a hydraulic ram piston 33 having a greater cross-sectional surface area but a smaller stroke than the preceding piston, its cylinder 34 being provided with a collar 35 for mechanically locking same with respect to the spindle carrier block 7.

To this end, (see also FIG. 8), the block 7 carries in this form of embodiment three locking studs 36 adapted to constitute a bayonet coupling with the collar 35. Therefore, the latter comprises three arcuate slots 37 shaped at one end for receiving freely the heads of said studs 36, the remaining portions of these slots 37 being adapted to slide on the shanks of these studs. The angular movement necessary for producing the locking bayonet coupling engagement is obtained by causing the mutual engagement of a toothed sector '35:: formed on said collar with a rack 38 slidably mounted in a guide 39 securedto the base plate 28 and connected to the piston of a hydraulic ram 40 having its cylinder secured to said base plate.

As shown in FIGS. 7 and 8, the movable assembly carrying the die section 26 also comprises a shoot 41 for supplying blanks to this die, such as the blank shown at 42. This shoot opens into a bore of die section 26 which is adapted to receive the blank and has slidably mounted therein a push member 43 rigid with a bar 44 mounted in turn for sliding movement in the piston 32 of the movable assembly and constituting, at its rear end, the piston 45 of a hydraulic actuator having its cylinder 46 secured to a rear cover 27a of body 27.

The shoot 41 is slidably engaged between two positioning guides 47 secured to the spindle carrier block 7 and is provided in its portion not shown in the drawings with a sorting device of known type permitting the access of the blanks only one by one into the shoot portion illustrated.

FIG. 6 shows a typical mounting of the actuator 18 controlling the feed movement of the tool roller; it will be seen that the supply of hydraulic control fluid to the two chambers of the movable cylinder 20 takes place in this case through the inner passage of the piston rod 22.

The movable cylinder 20 also constitutes a sleeve 48 receiving therein a stop screw 49 co-acting therewith, said stop screw 49 being keyed at 50 in an axial groove 51 formed in a control rod 52 extending through said screw and adapted to be actuated by means of an external handwheel 53. In fact, rotating this handwheel 53 will cause the screw 49 to move axially in relation to the sleeve 48 and thus adjust the permissible stroke of the cylinder of said actuator, within the limits permitted by the mutual engagement between said stop screw 49 and a limit stop 54 rigid with the frame structure, this adjustment permitting under these conditions the presetting of the feed stroke of the tool roller as a function of the desired inner diameter of the groove to be formed in the bearing race. Moreover, the screw 49 coacts with a movable stop member 55 adapted to produce the reversal ofthe stroke of actuator 18 at the end of a cycle and also to introduce a hydraulic damping or shock-absorbing action at the end of the stroke by throttling the corresponding exhaust of said actuator. During the return movement of the actuator to its inoperative position, in which it is illustrated, the rack 19 co-acts with a limit-stroke hydraulic damper 56 secured to the frame structure.

A typical form of embodiment of the transmission provided between the epicyclic gear train and the sleeves 4 and 6 is illustrated in FIG. 4 with reference numerals corresponding to those of FIG. 1 and will not be described further in detail, except for emphasizing the interposition of Oldham coupling or joints 8a, 9a in the chain driving the interconnected trains 8 and 9. Furthermore, it will be noted, if reference is made to FIG. 5, that the tool roller carrier spindle 1 is mounted in sleeve 4 on bearings 57 and 58.comprising two rows of rollers, which are self-aligning under an axial thrust, to provide a relatively accurate centering between the tool roller and the die. The sleeves are also mounted 'with a moderate coefficient of friction with the assis tance of needle rollers 59, 60 for sleeve 4 in sleeve 6, and 61, 62 for this sleeve 6 in said spindle carrier block 7.

The front face of the spindle carrier block 7 (FIGv 9) has pivotally mounted thereon by means of a pin 63 a deflector shutter 64 adapted to compel the finished race to emerge parallel to itself from the movable die section 26 so that it can slide freely during the ejection (for the ejected race may jump in any direction due to its inherent elasticity and may thus sometimes remain wedged between the two die sections), as will be explained presently, this deflector shutter being actuated by the piston rod of a pneumatic actuator 65 having its cylinder also pivotally mounted to said spindle carrier block 7.

Underlying the deflector shutter is an inclined shoot 66 for discharging the finished races, the lower end of said shoot beingsecured to the base plate 28.

In FIG. 9 it will be seen (as in FIG. 5)-that the fixed section 25 of the die is centered without play in the spindle carrier block 7 with the assistance of an annular set of wedging elements 67 screwed in the front cover 7a of said block.

The sequence of operation of the machine will now be described in detail. This sequence will be described with reference to its control means comprising the electro-hydraulic assembly or unit 24 illustrated, of which the component elements are shown in diagrammatic form or in'the form of symbols well known in the art, so that they will be mentioned only with reference to their specific functions illustrated in the drawings, in order to simplify the description, said control means being obvious to those skilled in the art and adapted to be replaced by other equivalent means without departing from.the basic principles of the invention.

The positions of the various movable assemblies illustrated in FIG. 3 correspond to the waiting condition of the tool roller 2 in the axis 0 and to the state of the openable die which is illustrated in FIG. 7.

1st step The hydraulic motor 3 is fed from pump 23 to drive the tool roller 2 for rotation about its axis; an output regulator 103 is inserted in the return line of the pump. A single fluid pressure is utilized throughout the hydraulic network and adjusted at the level of said pump as a function of the necessary rolling effort.

' causes the movable die section 26 to move towards the carrier assembly engages with its key-hole apertures 37 the locking studs 36. At the end of its stroke the movable assembly actuates a limit switch 71 controlling the energization of the winding 72 of another solenoidoperated valve 73 of which the distribution pattern illustrated is thus reversed, whereby the actuator 40 will cause, through the movement of its rack 38, the mechanical bayonet coupling between the collar 35 and studs 36. At the end of its stroke it actuates-another limit switch 74 controlling the energization of the winding 76 of a further solenoid-operated valves76 of which the distribution illustrated is thus reversed; under these conditions, the large-area piston 33 of the actuator which supports the movable die section 26 will close 1 the die sections 25, 26 with a greater force by causing the collar 35 of cylinder 34 to exert a pressure against the heads of the aforesaid locking studs 36. A pressure responsive switch 102 is provided for displaying the actuator closing pressure, since the very short stroke of piston 33 is not sufficient for operating limit switches. This closing of the two component elements or sections of the die by means of a relatively high hydraulic pressure and by reacting against a bayonet mechanical locking and coupling device permits through a very short stroke and therefore in a minimum time of ob taining workpieces that are free of burrs at the joint between the fixed section 25 and movable section 26 of said die, while limiting the efforts to be transmitted to the other parts of the machine. The limit switch 74 also controls the energization of the winding 77 of a solenoid-operated valve 78 of which the distribution pattern illustrated is reversed, whereby causing the forward stroke of the piston 45 of the actuator controlling the push member 43, the latter pushing the blank 42 into its rolling cavity formed in the aforesaid die section 25 and 26. At the end ofthe stroke of this push member another limit switch 79 is actuated for energizing the winding 80 of a solenoid-operated valve 81 monitoring the distributor 82 of which the distribution pattern illustrated is reversed, whereby the actuator 18 is supplied through an output regulator 102 in the direction to produce the approach movement of the tool roller 2 pressing the blank 42 against the peripheral surface of the die. At this time, the actuator closes through a cam rigid with sleeve 48 a passage switch 83 controlling the energization of the winding 84 of solenoid-operated valve 78, thus reversing its distribution pattern and causing the push member 43 to recede; output limiters 105 are provided for controlling the supply of hydraulic fluid to the piston 45. Then, this 1st step terminates (as shown in the diagram of FIG. 2) as illustrated in FIG. 11 in which the blank 42, obtained by wheel-cutting tubular stock, has a distored trapezoidal cross-sectional contour as illustrated.

This approach step 1 is now followed by the three operative or working steps, consisting in 2nd Step causing the tool roller 2 to penetrate into the blank 42 until it engages the entire rolling surface under constant-pressure conditions, by producing a gradually decreasing feed rate, after absorbing the elastic distortion of the blank (beginning of the step illustratcd in FIG. 12 and end of the step illustrated in FIGS. 13 and I) 3rd Step rolling without constant pressure the blank in the die by producing a gradually decreasing additional feed. until the blank fills completely the die with its outer surface (step illustrated in FIGS. 14 and 16) 4th Step forcing the blank laterally without constant pressure through a third gradually decreasing feed followed by a calibrating rolling movement without feed until the predetermined final dimensions of the race are obtained 5th Step producing a slow backwards movement while absorbing the stress distortions and producing the necessary calibration. At the end of this 5th step, a limit switch 85 is actuated by the stop screw 49 (via the aforesaid member 55), thus controlling the energization of the winding 86 of solenoid-operated valve 81 monitoring the distributor 82 of which the distribution pattern resumes the condition illustrated whereby, via actuator 18, the backward stroke of the tool roller, which corresponds to the 5th Step .of FIG. 2, is obtained. To this end, the circuit comprises a solenoid operated valve 106 and a deceleration valve 107 for adjusting the low-speed backward movement of the tool roller at the beginning of the backward stroke, said valve 106 being associated with an output regulator 108 adjusting the maximum backward rate of movement of the tool roller. Actuator 40, at the end of its stroke, o'perates another limit switch controlling the energization of winding 91 of valve 69 monitoring the distributor 70, of which the distribution pattern resumes the state illustrated so that piston 32 is caused to recede and the die is opened. The same limit switch 90 controls a solenoid-operated valve (not shown) for operating the actuator 65 and cause the deflector screen 61 to be lowered in front of the tool roller.

At the end of the backward stroke of piston 32 (in the movable die-carrier assembly) the main die section 26 carrying along the just rolled race will cause this race to engage push member 43, which will thus-eject the race.

The movable assembly, at the end of the backward stroke, actuates a limit switch 92 controlling the energization of the solenoid-operated valve controlling the actuator 65 in the direction to raise the deflector screen. The push member 43 and bar 44 are provided with central passages 43a, 44a extending from end to end and through which a die washing, cooling and lubricating fluid is fed from the rear end of the bar and ejected through the front end of the push member. After re-feeding the shoot 41 with a fresh blank, another sequence identical with the one described hereinabove can be accomplished.

A four-way manually controlled valve 110 connected to the pump 23 through a stop valve 111 controls the actuator for tipping the movable die-carrier assembly of FIGS. 7 and 10. Output limiters 112 connect this valve 110 to the actuator cylinder 31.

A pressure gauge 113 is provided for checking the single control fluid pressure across pump 23.

It willbe noted in FIG. 10 that the spindle carrier block 7 is inclined at about 45, in combination with a lubrication of the block bearings by means of lubricant flowing from feed means located at the top of this block and visible at 93 in FIG. 5, the oil exhaust being located at the lower point 91, and the oil return to an upper location is provided by pump means (not shown). This inclined arrangement also assists in reducing the overall dimensions of the machine, notably as far as floor space is concerned, while reducing in the feed step the rate of fall of the blanks and pressing these blanks against the feed nose to prevent a improper feeding of such blanks.

Pressure oil inlet ports for dismantling purposes are also contemplated at the orifice 95 where a roller-holder 96 is fitted into the spindle 1 coupled by screw-threads to a traction rod 97 for pulling the roller-carrier member with the assistance of actuator 101 at the orifice 98 where the spindle is fitted into its ball-bearing adjacent the tool roller, and

in a ram 99 formed at the rear of the spindle l, in which the cylinder receives the traction rod 97 formed with an internal inlet duct 100 and carries a piston 101 to permit the easy dismantling and refitting of the roller carrier 96.

The tool roller is driven through the medium of motor 3, rod 97, actuator 101, the cross-pins connecting said actuator 101 to spindle 1, this spindle 1 proper, then the roller carrier 96 wedged in said spindle 1.

When assembling the parts, oil is injected at 95 and 100 (the tool roller is pulled on a film of lubricant).

During the dismantling operation, oil is injected into the orifice 95, the conduit 100 being vented to the atmosphere (when the oil film is started under pressure between the spindle 1 and the roller carrier 96, the tool roller not retained at the rear being extracted due to the taper of its carrier member).

Although a specific form of embodiment of this invention has been described hereinabove and illustrated in the accompanying drawing, it will readily occur to those skilled in the art that various modifications and changes may be brought thereto without departing from the scope of the invention as set forth in the appended claims.

What is claimed is:

1. In a machine for rolling annular workpieces in an external die with a rolling tool roller operating in overhanging relationship in a blank of the workpiece to be rolled, said machine comprising:

a frame structure,

first and second sleeves, said first sleeve being disposed eccentrically in said second sleeve,

a spindle fitted eccentrically in said first sleeve,

said tool roller being rigidly connected to one end of said spindle,

said second sleeve being rotatably mounted in said frame structure,

drive means for rotating said sleeves at the same speed.

means for angularly displacing said sleeves relative to each other for controlling the feed movement of the tool roller,

a motor for rotatably driving said spindle and said tool roller at such speed that the relative speed of the tool roller at a peripheral point thereof approaching a blank to be rolled is substantially zero,

said drive means comprising an epicyclic gear train operatively connected through two rotating members of said gear train to said sleeves, said rotating members being coactable with a third member of said gear train,

said third member being responsive to said angularly displacing means and constituting a reaction memher, the angular setting of which is controlled by said angularly displacing means as a function of the desired rate of feed movement of the tool roller.

2. In a machine as set forth in claim 1, wherein the angular displacement imparting means comprise a hydraulic actuator having its fluid supply regulated for both pressure and output.

3. In a machine as set forth in claim 1, wherein said sleeves are rotatable in bearings comprising rolling bodies and said train comprises at least one homokinetic eccentric coupling.

4. In a machine as set forth in claim 3, wherein the axes of the bearings are inclined to the vertical whereby lubrication of said bearings is obtained by free flowing from an oil feed located in the upper portion of the machine.

5. In a machine as set forth in claim 1, wherein said tool roller spindle is mounted in the first sleeve of the pair on bearings comprising double rows of rollingcontact members, of which the setting under axial thrust is such as to take up the spindle bearing play.

6. In a machine as set forth in claim 1, further comprising pressure oil inlets for dismantling purposes at the fittings of a tool roller carrier member in the spin dle, in the spindle on a bearing adjacent to said tool roller, and in an actuator located at the end of said spindle.

7. In a machine as set forth in claim 2, wherein the hydraulic actuator comprises a stop adjustment device of the manual control screw type for adjusting the end of the permissible stroke, whereby the feed movement of the tool roller can be adjusted as a function of the predetermined inner diameter of the race.

8. In amachine as set forth in claim 2, wherein return movement of the tool roller is adjusted at low speeds due to reversibility of the kinematic chain and to a throttling of the hydraulic circuit during the return stroke of the rack.

9. In a machine as set forth in claim 1, further comprising a die comprising a first die section rigid with the frame structure and a movable device comprising a second openable die section carried by a movable assembly, means for closing and locking said die, a blank feed shoot and a central push member for positioning the blanks to be rolled and for ejecting the rolled blanks.

10. In a machine as set forth in claim 9, wherein the means for closing and locking the die comprise a hydraulic actuator having a piston of large cross-sectional area and reduced stroke which reacts against a studand-slot mechanical locking device of the bayonet type operating by translation and then rotation of said movable assembly by means of corresponding rams.

11. In a machine as set forth in claim 9, further comprising duct passages in said push member for positioning and ejecting the blanks, in order to supply washing, cooling and lubricating fluid to said die.

12. In a machine as set forth in claim 9, wherein said feed shoot comprises a sorting device capable of presenting only one blank per cycle.

13. In a machine as set forth in claim 9, further comprising a movable deflector screen for intervening betweeen the blank and the rolling tool roller when the die is opened and before said blank is ejected,

14. In a machine as set forth in claim 9, wherein said first die section is centered in the frame structure by means of an annular set of wedging blocks.

15. In a machine as set forth in claim 9, wherein said movable device is pivotally mounted about a pin for bringing the axis of said second die in a vertical position in order to release two elements of the die for inspection and tool replacements.

\ i i a .k 

1. In a machine for rolling annular workpieces in an external die with a rolling tool roller operating in overhanging relationship in a blank of the workpiece to be rolled, said machine comprising: a frame structure, first and second sleeves, said first sleeve being disposed eccentrically in said second sleeve, a spindle fitted eccentrically in said first sleeve, said tool roller being rigidly connected to one end of said spindle, said second sleeve being rotatably mounted in said frame structure, drive means for rotating said sleeves at the same speed, means for angularly displacing said sleeves relative to each other for controlling the feed movement of the tool roller, a motor for rotatably driving said spindle and said tool roller at such speed that the relative speed of the tool roller at a peripheral point thereof approaching a blank to be rolled is substantially zero, said drive means comprising an epicyclic gear train operatively Connected through two rotating members of said gear train to said sleeves, said rotating members being coactable with a third member of said gear train, said third member being responsive to said angularly displacing means and constituting a reaction member, the angular setting of which is controlled by said angularly displacing means as a function of the desired rate of feed movement of the tool roller.
 2. In a machine as set forth in claim 1, wherein the angular displacement imparting means comprise a hydraulic actuator having its fluid supply regulated for both pressure and output.
 3. In a machine as set forth in claim 1, wherein said sleeves are rotatable in bearings comprising rolling bodies and said train comprises at least one homokinetic eccentric coupling.
 4. In a machine as set forth in claim 3, wherein the axes of the bearings are inclined to the vertical whereby lubrication of said bearings is obtained by free flowing from an oil feed located in the upper portion of the machine.
 5. In a machine as set forth in claim 1, wherein said tool roller spindle is mounted in the first sleeve of the pair on bearings comprising double rows of rolling-contact members, of which the setting under axial thrust is such as to take up the spindle bearing play.
 6. In a machine as set forth in claim 1, further comprising pressure oil inlets for dismantling purposes at the fittings of a tool roller carrier member in the spindle, in the spindle on a bearing adjacent to said tool roller, and in an actuator located at the end of said spindle.
 7. In a machine as set forth in claim 2, wherein the hydraulic actuator comprises a stop adjustment device of the manual control screw type for adjusting the end of the permissible stroke, whereby the feed movement of the tool roller can be adjusted as a function of the predetermined inner diameter of the race.
 8. In a machine as set forth in claim 2, wherein return movement of the tool roller is adjusted at low speeds due to reversibility of the kinematic chain and to a throttling of the hydraulic circuit during the return stroke of the rack.
 9. In a machine as set forth in claim 1, further comprising a die comprising a first die section rigid with the frame structure and a movable device comprising a second openable die section carried by a movable assembly, means for closing and locking said die, a blank feed shoot and a central push member for positioning the blanks to be rolled and for ejecting the rolled blanks.
 10. In a machine as set forth in claim 9, wherein the means for closing and locking the die comprise a hydraulic actuator having a piston of large cross-sectional area and reduced stroke which reacts against a stud-and-slot mechanical locking device of the bayonet type operating by translation and then rotation of said movable assembly by means of corresponding rams.
 11. In a machine as set forth in claim 9, further comprising duct passages in said push member for positioning and ejecting the blanks, in order to supply washing, cooling and lubricating fluid to said die.
 12. In a machine as set forth in claim 9, wherein said feed shoot comprises a sorting device capable of presenting only one blank per cycle.
 13. In a machine as set forth in claim 9, further comprising a movable deflector screen for intervening betweeen the blank and the rolling tool roller when the die is opened and before said blank is ejected.
 14. In a machine as set forth in claim 9, wherein said first die section is centered in the frame structure by means of an annular set of wedging blocks.
 15. In a machine as set forth in claim 9, wherein said movable device is pivotally mounted about a pin for bringing the axis of said second die in a vertical position in order to release two elements of the die for inspection and tool replacements. 